Whelk is a word used for several different families of marinegastropods. They are found in temperate and tropical waters, and are used by humans as food. However, the name is properly used for the family Buccinidae, sometimes called the "true whelks".

In the British Isles and the Netherlands, where the word whelk probably originated, the word "whelk" is applied to a number of species in the family Buccinidae, especially Buccinum undatum, an edible European and Northern Atlantic species.

In North Americawhelk refers to several large edible species in the genera Busycon and Busycotypus within the family Melongenidae. These are sometimes called Busycon whelks. In the United States, the invasive Murex Rapana venosa is referred to as the Veined rapa whelk or Asian rapa whelk.

In the English-speaking islands of the West Indies, the word whelks or wilks (the word is both singular and plural) is applied to a large edible top shell, Cittarium pica, also known as the magpie or West Indian top shell.

True whelks are carnivores and scavengers.[1] They feed on clams, carrion, and sometimes even on detritus. Their sense of smell is very well-developed; they can sense chemical signals from their prey from a considerable distance. Many whelks can bore through the shell of bivalves. Because of this, they can cause harm in oyster farms. Whelks can even attack fish caught in a net by extending their probosces to twice the length of their own bodies.